Self retracting catheter needle apparatus and methods

ABSTRACT

Method and apparatus associated with safe retraction of medical needles after use. Embodiments are disclosed for self-retracting needle systems for both blood withdrawal and catheter insertion systems. Invention manufacture requires only a minimal number and complexity of parts such that a projected manufacturing cost is potentially low enough to permit the apparatus to be cost competitive with contemporary non-self retracting needle systems. Methods for making and assembling the disclosed embodiments is also disclosed. Energy storing retracting mechanisms comprise elastic tubing and vacuum generating piston parts and may be used for both blood withdrawal and catheter needles. Triggerable release mechanisms generally comprise two parts or two segments of one part molded about a medical needle. Each release mechanism involves one part or segment which is securely affixed to the needle and one part or segment which is free to slide and rotate about the needle. The blood withdrawal embodiment effectively inhibits regurgitant flow from the needle. The catheter insertion embodiment captures blood effluent from the catheter upon retraction of the needle. One catheter embodiment comprises a compressibly closable member used to occlude blood flow after the needle is withdrawn. In all embodiments, needle retraction is a single handed operation permitting a technicians other hand to be used in wound care. Use of frangible parts permits the apparatus housing to be hermetically sealed and used as a transport container to further reduce apparatus costs.

CONTINUATION

This application for patent is a continuation-in-part of co-pending U.S.patent application Ser. No. 08/370,728 filed Jan. 10, 1995.

FIELD OF INVENTION

This invention relates generally to medical needle apparatus and methodsand particularly to apparatus comprising medical needles which areself-retracting from an extended position at which the needle is used toa retracted position where the needle is fully withdrawn to be encasedwithin a housing for safe disposal. Further, the invention is related tomedical products which may only be used once to eliminate crosscontamination from one patient to another and to those medical productswhich have sterile parts inherently protected from contamination withoutneed of additional packaging apparatus.

PRIOR ART

Problems associated with inadvertent needle sticks are well known in theart of blood withdrawal, transdermal medication injection, catheteremplacement and other medical procedures involving uses of medicalneedles. Ever increasing attention is being paid to needle stickproblems due to the contemporary likelihood of being exposed to AIDS andHepatitis.

Commonly, procedures involving needle withdrawal require a technician touse one hand to place pressure at the wound site where a needle is beingwithdrawn while removing the needle apparatus with the other hand. It iscommon practice for the tending technician to give higher priority tocare for the wound than is given to disposal of a needle. Such priorityeither requires an available sharps container within ready reach oranother means for safe disposal without leaving the patient's side.Providing adequate care is often compounded by patient condition andmental state (e.g. in burn units and psychiatric wards). Under suchconditions, it is often difficult, if not impossible, to takeappropriate procedures to properly dispose of a used, exposed needlewhile caring for a patient.

Widespread knowledge and history associated with needle care anddisposal problems have resulted in conception and disclosure of a largenumber of devices, each of which represents an attempt to provide notonly a solution to the problem of needle sticks, but a device which iscommercially viable (cost and price competitive with currently usednon-self retracting devices). Though some devices describe applicationin the area of blood withdrawal (see U.S. Pat. Nos. 4,850,374 (NydiaDiaz-ramos) and 5,195,985 (Hall)), most contemporary related art isdirected toward syringes and like devices. Broadly, related art may beclassified into two categories, devices which operate manually anddevices which comprise self-contained needle retraction.

Examples of manually operated medical needle devices are provided inU.S. Pat. Nos. 4,676,783 (Jagger et al.), 4,83,936 (Schroeder),4,909,794 (Haber), 4,978,340 (Terrill et al.), 4,995,870 (Baskas),5,098,402 (Davis), 5,180,370 (Gellespie), 5,188,599 (Botich et al.),5,195,985 (Hall), 5,205,823 (Zdeb), 5,205,824 (Mazur), 5,215,533 (Robb),and 5,256,153 (Hake). Manual withdrawal is generally a two-handedprocedure, making wound care a secondary step or requiring an addedmedical technician.

Examples of self-retracting devices are found in U.S. Pat. Nos.4,946,446 (Vadher), 4,955,870 (Ridderheim et al.), 4,966,593 (Lennox),4,988,339 (Vadher), 4,994,034 (Botich et al.), 5,114,404 (Paxton etal.), 5,147,303 (Martin), 5,092,853 (Couvertier), 5,246,428 (Falknor),5,254,099 (Karacina), and 5,267,976 (Guerineau et al.). Guerineau et al.discloses self-retraction resulting from a vacuum force while othersdisclosed above generally disclose self-retraction resulting fromrelease of a cocked or biased spring.

Generally, other than acceptance of the type of operation offered bysuch devices, commercial viability is dependent upon manufacturing cost.Purchase decisions in the area in which these devices are used are verycost sensitive. If gains in either improvement in safety or in laborsavings are not found to be sufficiently competitive with contemporarycompetitive items, the devices are usually not found to be commerciallyviable. Motivation for providing a cost Competitive self-retractingneedle apparatus coupled with improved safety of use of the apparatusresulted in conception of the instant invention disclosed herein.

A catheter patent application Ser. No. 08/251,092 filed May 31, 1995,with notification of allowance mailed Dec. 8, 1994 (Shaffer), relatesgenerally to the field of catheters for venous or arterial cannulation.Such catheters are generally inserted into a blood vessel with a hollowinsertion needle having a needle hub. Specifically, Shaffer relates toan occludable catheter apparatus for blocking flow of blood from thecatheter after withdrawal of the insertion needle. The apparatusincludes a catheter hub having a side wall with a stiff but compressibletubular side wall portion, a proximal end, a distal end, and a catheterextending axially outward from the distal end. Two spaced apart membersprotrude tangentially outward from the hub tubular side wall portion,and each member contains a stiff structural appendage extending into theside wall portion. The members are pressed toward each other to collapsethe hub side wall portion. The catheter hub contains compressible,resilient sealing material such as a foam rubber which sealinglycompresses about an axial opening during hub collapse. To use theapparatus, the needle and needle hub are inserted into the apparatusthrough the catheter hub. The insertion needle and catheter penetrate ablood vessel, and then the needle is withdrawn from the catheter andcatheter hub. As the needle is withdrawn, the members are gripped andsqueezed by the medical provider and the sealing material is therebycompressed to prevent blood from escaping from the catheter. The sealingmaterial closes the hub completely after the tip of the needle passesout of the hub to prevent blood from escaping until, as an example, aninfusion set is connected to the catheter hub proximal end. The lockingmembers may optionally include latching attachments for holding themembers together after the catheter hub is collapsed.

BRIEF SUMMARY AND OBJECTS OF THE INVENTION

In brief summary, this novel invention alleviates known major problemswhich result from injury-related needle sticks which occur as needletips are bared at the end of a needle insertion procedure. In apreferred embodiment, operation of the invention involves extension of acovered needle by frangibly separating the needle cover from a housingand pulling the cover and needle from the device for use. The act ofpulling the cover and needle from the device energizes a force storingmemory element and cocks a releasable latch. The cover is removed fromthe needle, and the needle is used in a medical procedure (e.g. foracquiring a blood sample or for catheter insertion).

Once the procedure is complete, a simple distortion of a portion of thehousing, preferably by squeezing the housing by the thumb and forefingerof one hand, retracts the needle safely into the housing. It isimportant to note that the needle can be removed by simple squeezingaction of an attending technician's hand, leaving the technician's otherhand free for other concurrent medical procedures, such as care of thewound site from which the needle is withdrawn. After withdrawal, theneedle is fully enclosed and contained, permitting the needle apparatusto be laid aside without fear of an inadvertent needle stick while fullattentive care is provided to the patient.

In a blood sampling embodiment, the invention comprises ahousing/transport container, a needle/hub assembly and a barrel/hubcomponent. In preferred embodiments, apparatus of the instant inventionrequire as few as three molded parts, each part being representative ofthe container, assembly and component mentioned above.

The housing/transport container is preferably molded as a singlemulti-cylinder part. The part consists of two cylinders, an innercylinder and an outer cylinder, and a protective flap connected by aliving hinge to the outer cylinder. The inner and outer cylinders aremutually closed at one end and open at the other. The inner cylinderforms a needle cover which has an attachment (e.g. a female threaded orbayonet coupling) for joining to a male connection to provide aseparable attachment to the needle/hub assembly. The outer cylinder ofthe housing/transport container is preferably hermetically sealed to thebarrel/hub component to form a closed housing which is capable of beingused as a transport package which maintains needle sterility untilopened at the beginning of a medical procedure.

Though other forming processes may be used, needle/hub assembly ispreferably formed as a single part which is injection molded about amedical needle. The assembly comprises the medical needle, (a) afore-portion of the part more proximal to the sharp end of the needleand disposed about the needle and juxtaposed with a portion of theelongated length of the needle but left by the molding process to movefreely upon the needle and (b) an-aft portion which is more distal fromthe sharp end of the needle and also disposed about the needle butfirmly and securely affixed to the needle. The fore-portion comprisesthe male connection which separably affixes to the needle cover by theconnection earlier referenced. The fore-portion also comprises at leastone latch which locks to a portion of the container when the needle ispulled forth from the container for use. The act of pulling the needlefully forth to a locked position cocks a needle portion of the needleassembly in position for release and retraction at the end of themedical procedure.

The container comprises a complementary catch for the latch. Uponrelease from the cocked position, the fore-portion is separated from theaft-portion to permit the needle to be retracted into the protectivehousing leaving the fore-portion to cover a major portion of the holecreated when the cover is separated from the container.

The aft-portion of the needle/hub assembly comprises a hub which isaffixed to a proximal end of a force storing memory element which isenergized when the needle is pulled from the housing. Preferably, whenthe apparatus is used in blood sampling, the needle/hub assemblycomprises a pathway for fluid flow to the memory element which alsocomprises a pathway for fluid flow.

The barrel/hub component comprises a hub which is affixed to the distalend of the memory element. In a preferred embodiment of the inventioncomprising a memory element which integrally incorporates a fluid flowpathway therethrough, the hub also contains a fluid flow pathway. For anapplication involving blood withdrawal to a receiving and bloodwithdrawing container (e.g. a vacuum blood draw tube, such as the BectonDickenson Vacutainer®), the pathway comprises a second needle tube whichis similar to needles used in conjunction with the Becton DickensonVacutainer®. The barrel/hub also comprises a surface disposed about thememory element side of the hub which is joined to the open end of theouter cylinder of the housing/transport container to form thehermetically sealed closed housing.

Though the memory element may comprise a plunger mechanism which draws avacuum when the needle is extended to cock the apparatus forself-retraction or a spring, the memory element is preferably an elastictube in blood sampling embodiments. It should be noted that use of anelastic tube provides opportunity for use of the tube to transport fluidas a tube connected at its ends and stretched therebetween maintains apatent pathway even when stretched. For the elastic tube to be used asthe fluid pathway, the tube material must be effectively inert to bloodproducts. Latex is an example of such material.

It is noted that, except for needles which are captured as parts ofinjection molded parts and an extruded tube, all parts are injectionmolded.

In a preferred embodiment, the inner cylinder is frangibly separablefrom the outer cylinder at the closed end. The hole made by separatingthe two cylinders is preferably substantially and permanently filled bya part of the foreportion of the needle/hub assembly as part of thecocking procedure.

Cocking of the release mechanism is triggered for release by depressinga compliable or compressible portion of the outer cylinder. That portionof the outer cylinder is protected from inadvertent depression by theprotective flap. The flap is retained to protect the portion, forexample by a snap-in groove connection, and removed by a simple flippingmovement of a thumb or forefinger. The flap is preferably molded as anintegral part of the outer cylinder connected thereto by a living hinge.

In a catheter insertion embodiment, the invention comprises ahousing/transport receptacle, a needle/hub component and a housingclosure module. In preferred embodiments, apparatus of the instantinvention require as few as three injection molded parts, each partbeing representative of the receptacle, the element and the housingclosure module mentioned above.

The housing/transport receptacle is preferably molded as a singlemulti-cylinder part. The part consists of two cylinders, an innercylinder and an outer cylinder, and a protective flap connected by aliving hinge to the outer cylinder. The inner and outer cylinders aremutually closed at one end and open at the other end. The inner cylinderforms a needle cover which has an attachment (e.g. a female threaded orbayonet coupling) for joining to a male connection to provide aseparable attachment to the needle/hub element. The outer cylinder ofthe housing/transport receptacle is preferably hermetically sealed tothe housing closure module to form a closed housing, capable of beingused as a transport package by maintaining needle sterility until openedat the beginning of a medical procedure.

The needle/hub element is preferably formed as a single injection moldedpart about a medical needle. The element comprises (a) the medicalneedle, (b) a fore-portion of the part more proximal to the sharp end ofthe needle and molded about a predetermined segment of the needle and(c) an-aft portion which is more distal from the sharp end of the needleand also molded about the needle.

The fore-portion is juxtaposed with a portion of the elongated length ofthe needle but slidably free of the needle after the molding process.The fore-portion comprises the male connection which is separablyaffixed to the needle cover during assembly. The fore-portion alsocomprises at least one latch which locks to a portion of the receptaclewhen the needle is pulled forth from the receptacle for use. During thepull, the fore-portion is securely affixed to the aft-portion. Theaft-portion is firmly and securely affixed to the needle in the moldingprocess. The act of pulling the fore-portion, therefore, results in aneedle portion of the needle/hub element being emplaced in a positionfor use. Pulling the fore-portion fully to a locked position cocks theneedle portion in position for release and retraction at the end of themedical procedure.

The receptacle comprises a complementary catch for the latch. Uponrelease from the cocked position, the fore-portion separates from theaft-portion causing the needle to be retracted into the protectivehousing/transport receptacle.

Though the memory element may comprise an elastic tube or a spring, thecurrently preferred memory element comprises a piston part similar topistons used in disposable syringes. As it is important to provide ablood flash viewing means in IV catheter insertion apparatus, a partwhich is intermediate between the needle and plunger apparatus comprisesa translucent or transparent section into which blood is selectivelypermitted to flow and be seen by an operating technician.

In one embodiment, an attached catheter hub contains compressible,resilient sealing material such as a foam rubber which compresses toform a seal during hub collapse, the sealing material having an axialopening, similar to the sealing material disclosed in Shaffer, supra.

Accordingly, it is a primary object to provide a novel and improvedblood withdrawal device comprising a housing which maintains sterilityof a medical needle and other internal parts of the device until use andwhich automatically fully retracts the needle into the housing afteruse.

It is a key object to provide the blood withdrawal device with anattached barrel for a blood acquisition vacuum tube (e.g. a Vacutainer®made by Becton Dickenson).

It is another key object to provide a needle cover for the device whichis made as a part of the housing, but which is frangibly separable fromthe housing, thereby providing an exit pathway for the cover and theneedle.

It is an important object to provide a means for releasing a cockedneedle assembly by distorting a portion of the housing rather thanrequiring a button or other mechanical device to project through thehousing wall.

It is also an important object to protect the portion which is distortedfrom being distorted during insertion and use of the needle and toremove the protection with a single digit motion immediately prior toretracting the needle.

It is an object to provide parts disposed at each end of the devicewhich facilitate manually extending the needle for use.

It is another primary object that the device be usable but once and theneedle be safely enclosed when retracted.

It is a very important object that the device be made with as fewinjection molded parts as possible.

It is therefore an important object that the device be made from as fewas three injection molded parts (and as few as three extruded parts).

It is also an important object that a part used to pull the needle,latch the needle assembly into a cocked position, and separate torelease the needle, for subsequent retraction, be moldable in a singlemolding step.

It is an object to provide an embodiment of the invention comprising alatch which is releasable by franging a section of the needle assembly.

It is a significant object to provide a manufacturing method forassembly of the device which is compatible with automatic assemblyequipment.

It is an object to provide a force storing memory element which storesenergy as the needle assembly is cocked and which provides retractingforce upon release of the needle assembly.

It is a meaningful object to provide a memory element which comprises anenclosed fluid flow pathway for withdrawn blood.

It is a consequential object to provide an essentially closed pathwayfor regurgitant blood flow during retraction.

It is an object to provide a means for connecting the needle cover tothe needle assembly during device manufacture which does not put unduestress upon a frangible part.

It is an object to provide a blood withdrawal device which is simple touse.

It is still another object to provide a means for seeing a blood"flashback" within the device as influent blood courses into the devicefrom a pierced blood vessel.

It is yet another primary object to provide a novel and improved IVcatheter insertion apparatus comprising a housing which maintainssterility of a medical needle, a catheter and other internal parts ofthe apparatus until use and which automatically fully retracts theneedle into the housing after use.

It is a key object to provide the blood withdrawal apparatus whichprovides for containment of blood exiting the catheter immediately uponretraction of the needle.

It is another key object to provide a needle cover for the apparatuswhich is made as a part of the housing, but which is frangibly separablefrom the housing, thereby providing an exit pathway for the cover andthe needle.

It is an important object to provide a means for releasing a cockedneedle assembly by distorting a portion of the housing rather thanrequiring a button or other mechanical apparatus to project through awall of the housing.

It is also an important object to protect the portion which is distortedfrom being distorted during insertion and use of the needle and toremove the protection with motion of a single digit immediately prior toretracting the needle.

It is an object to provide parts disposed at each end of the apparatuswhich facilitate manually extending the needle for use.

It is another primary object that the apparatus be usable but once andthe needle be safely enclosed when retracted.

It is a very important object that the apparatus be made with as fewmolded parts as possible.

It is therefore an important object that the apparatus be made from asfew as three injection molded parts (and as few as three extrudedparts).

It is also an important object that a part pulled to extend the needle,latch the needle assembly into a cocked position, and separate torelease the needle, for subsequent retraction, be molded in a singlemolding step.

It is an object to provide, in one embodiment of the invention, a latchwhich is releasable by franging a section of the needle assembly.

It is a significant object to provide a manufacturing method forassembly of the apparatus which is compatible with automatic assemblyequipment.

It is an object to provide a force storing memory element which storesenergy as the needle assembly is cocked and which provides retractingforce upon release of the needle assembly.

It is a consequential object to provide an essentially closed pathwayfor regurgitant blood flow upon and during retraction.

It is an object to provide an IV catheter insertion apparatus which issimple to use.

It is still another object to provide a means for seeing a blood"flashback" within the device as influent blood courses into the devicefrom a pierced blood vessel.

It is an object to provide a catheter embodiment having a hub containingcompressible, resilient sealing material such as foam rubber which maybe sealingly compressed by collapsing the hub, the sealing materialhaving an axial opening which is closed only when the sealing materialis compressed,

These and other objects and features of the present invention will beapparent from the detailed description taken with reference toaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective of a sealed blood withdrawal device, showing theoutside of the device housing.

FIG. 2 is a perspective of the blood withdrawal device seen in FIG. 1from which a needle cover and associated needle (not shown) have beenpulled by first frangibly breaking away the needle cover from a portionof the housing.

FIG. 3 is a perspective of the blood withdrawal device seen in FIG. 2showing a needle bared by cover removal and a partially removed sealwhich covered and protected the internal portion of a blood withdrawalvacuum tube barrel, relative to the needle.

FIG. 4 is a perspective of the blood withdrawal device showingdisplacement of a flap, seen in place in FIG. 3, the displacementpermitting an area of the housing previously under the flap to bedistorted, the distortion resulting in retraction of the needle into thehousing.

FIG. 5 is a greatly magnified perspective of a medical needle having aportion of the needle treated with a mold release.

FIG. 6 is an exploded side view of a blood withdrawal device with someportions segmented and other portions removed for better presentation.

FIG. 7 is a lateral elevation of a needle/hub assembly which initiallyresides within the housing and is separably affixed to the cover.

FIG. 8 is a top elevation of the needle/hub assembly seen in FIG. 7.

FIG. 9 is a bottom elevation of the needle/hub assembly seen in FIG. 7.

FIG. 10 is an exploded perspective of a section of the needle/hubassembly seen in FIGS. 7-9 and a valve leaflet which is used to restrictregurgitant flow from the device.

FIG. 10A is a perspective of a section of a needle/hub assembly showinga valve leaflet affixed by molding to the needle/hub assembly through aliving hinge.

FIG. 11 is an exploded view of the device of FIG. 6 with a firstassembly step completed.

FIG. 12 is an exploded view of the device of FIG. 7 with a secondassembly step, comprising attaching an elastic tube, completed.

FIG. 13 is an exploded view of the device of FIG. 7 with a thirdassembly step of attaching the elastic tube to the barrel part. (Notethat a perspective of a completely assembled device is seen in FIG. 1.)

FIG. 14 is a section of a used device prior to retracting the needle.

FIG. 14A is a perspective of a needle/hub assembly with portions removedfor clarity of presentation.

FIG. 15 is a lateral elevation of an elastic tube stretched between hubsof the barrel and needle/hub assembly parts.

FIG. 16 is a side elevation of an alternative embodiment of a needle/hubassembly showing a first part which is molded about and securely affixedto the needle and a second part which is molded about the needle butwhich is free to slide longitudinally along the needle.

FIG. 17 is a side elevation of the embodiment seen in FIG. 16 with theslidable part moved to an adjoining position relative to the first part.

FIG. 18 is a longitude section of a portion of the device showing thealternate needle/hub embodiment in three different positions in thedevice.

FIG. 19 is a section similar to the section seen in FIG. 18, but rotated90°.

FIG. 20 is a perspective with some parts removed for clarity of a barrelsection associated with the embodiment seen in FIGS. 16-20.

FIG. 21 is an exploded perspective of the device comprising thealternate needle/hub embodiment.

FIG. 22 is a perspective of an alternate embodiment of the inventionshowing a totally enclosed IV catheter insertion assembly.

FIG. 23 is a longitudinal section of the assembly seen in FIG. 22.

FIG. 24 is a side elevation of a catheter and needle with a compressiblematerial section disposed proximal to the connector end of the catheter.

FIG. 25 is a section taken along lines 25--25 of FIG. 24, showing asection of the compressible material and an orifice therethrough.

FIG. 26 is a section similar to the section of FIG. 25 showing thematerial compressed and the orifice substantially closed thereby.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

In this description, unless a specific object is referenced, the termproximal is used to indicate the segment of a device normally closest tothe patient when it is being used. In like manner, the term distalrefers to the other end. Reference is now made to the embodimentsillustrated in FIGS. 1-23 wherein like numerals are used to designatelike parts throughout. Generally parts having similar form and functionto parts earlier cited are enumerated with prime numerals of the earliercited parts.

Reference is now made to FIG. 1 wherein an embodiment according to theinvention of a blood withdrawal device 10 is seen. As seen in FIG. 1,device 10 comprises a barrel section 20 and a needle containment section30. In a completely assembled device, section 20 is securely andhermetically sealed to section 30 along circular line 32.

Barrel section 20 comprises a planar seal 40 and a pair of left andright ear or handle parts, designated 50 and 60, respectively, and ahollow barrel 70. Planar seal 40 is adhesively attached to barrelsection 20 within a plane area defined by continuous line 72 such thatthe hollow of barrel 70 is maintained in a sterile condition prior touse. To use device 10, seal 40 is manually removed. Of course, adifferent kind of seal may be used, such as a snap-on part which may bemolded as a tether-attached part of section 20. The snap-on part is notshown, but production of such parts is well known in the art. A moredetailed description of the internal parts of barrel 70 is providedhereafter.

Needle containment section 30 comprises an elongated tube 80, a flap 90,a proximally facing front face plate 100 and a pull-ring 110.Importantly, it should be noted that pull-ring 110 is separable fromfront face plate 100 at a frangibly detachable segment 112, which isdescribed in more detail hereafter.

Steps related to the use of device 10 are seen in FIGS. 2-4. In FIG. 2,pull-ring 110 has been detached from front face plate 100. Detachment ofsegment 112 produces a ragged collar 114. As pull-ring 110 is advancedfrom face plate 100, a needle cover 120 which is firmly affixed andintegrally molded with pull-ring 110 appears through a hole created byremoval of collar 114. Once pull-ring 110 is fully extended, a yoke 130snaps into place about the hole produced by removal of collar 114.Structure of yoke 130 and related parts are disclosed in more detaillater.

A next step is to remove seal 40 from barrel section 20. Seal 40 is seento be in process of being removed in FIG. 3. In a next step, pull-ringand needle cover 120 are removed from device 10. Needle cover 120 ispreferably attached to a hub 132 by a rotatably detachable coupler, suchas by a threaded or bayonet type connector. In any event, the couplingattachment between hub 132 and cover 120 must be able to support a pullforce at least as great as a retarding force imposed in the oppositedirection by a retracting mechanism which is energized by the pullextending cover 120 until engagement of yoke 130. As seen in FIG. 3, ahollow medical needle 140 is bared upon removal of cover 120.

As best seen in FIG. 4, flap 90 comprises a living hinge attachment 142to elongated tube 80. Flap 90 also comprises a hook latch 144 which isnormally engaged in a groove 146 proximally disposed in tube 80. Locatedflap 90, when disposed in groove 146 is a deformable area 148 of tube80. While flap 90 is disposed and latched into groove 146, area 148 isfully protected from any deformation. Thus, during a medical bloodwithdrawal procedure, flap 90 is latched into groove 146. Once a bloodacquisition procedure has been completed, flap 90 is rotated by actionof a single digit after which needle 140 may be retracted by depressingarea 148. Retraction places needle 140 safely inside tube 70. Onlyaccess inside tube 70 and needle 140 is a hole 150 in hub 132 which isthe essentially the same diameter as the cross sectional diameter ofneedle 140. Further, as is explained later, needle 140 is securely heldwell away from hole 150. Retraction mechanisms for needle 140 aredescribed in detail hereafter.

Also seen in FIG. 4 is a snap-on cover 151 affixed by a tether 152 tohandle 60. Cover 151 is an alternative embodiment to seal 40. Cover 151has the advantage of not requiring a cover part to be made separatelyfrom barrel section 20. However, to provide assurance that cover 151 hasnot been opened previous to a procedure to which device 10 is uniquelydedicated, an additional seal, such as a shrink wrap about exterioredges of cover 151 and related parts of handles 50 and 60 and tube 70should be used. Making of parts attached by tether is well known in theart.

Reference is now made to FIG. 6 wherein an exploded view of oneembodiment of device 10 is seen to comprise needle containment section30, a needle/hub part 160, a valve disk 170, an elastic tube 180 andbarrel section 20. Attention is first drawn to needle/hub part 160 whichis seen magnified for more clarity of details in FIGS. 7-9.

Part 160 comprises medical needle 140, a fore part 190 proximal to thesharp end of needle 140, a central part 192, and an aft part 194.Normally unseen extensions of needle 140 through part 160 is indicatedby double dashed lines 196 and 198 for clarity of extent of needle 140passage through part 160. Fore part 190 comprises yoke 130, hub 132, anannular groove 200, an annular stop 202 and an elbow shaped extension204 which comprises an outwardly extending part 206. Central part 192comprises a frangible bridge 208 and a support 210. Aft part 194comprises a short shaft 212 and a tube hub 214. Part 160 is preferablymolded as a single part with end-to-end continuity between parts 190,192 and 194. Aft part 160 is firmly and securely affixed to needle 140while fore part 190 is only slidably affixed and otherwise free to movealong needle 140 when bridge 208 is franged.

Hub 132 comprises a releasable connector component which may be in theform of a threaded surface 216 as seen in FIGS. 7-9. Yoke 130 comprisesa sloped annular face 218 and a transverse latching surface ring 220distal to and juxtaposing face 218. Groove 200 is interposed between andcontiguous with ring 220 and stop 202. Function and use of yoke 130,groove 200 and stop 202 are described in detail hereafter.

As best seen in FIG. 7, extension 204 protrudes distally from stop 202via a lateral bar 222 to an elbow 224 where extension makes anorthogonal bend to provide upward and outwardly extending part 206.Bridge 208 is a part which is narrow in both transverse dimensions togovern the degree of pressure required to frange bridge 208 fromextending part 204. One of the surprising aspects of the instantinvention is the force which may be placed upon bridge 208 when pullingagainst a force retaining memory element used in retracting needle 140without breaking bridge 208 away from extension 204. Clearly, if even anominal torque is place upon bridge 208 during a pull, bridge 208 mightbreak. However, close tolerances maintained between needle 140 and forepart 190 reduce and keep such torque to a level which does not causebridge 208 to break. The method for achieving close tolerances betweenneedle 140 and fore part 190 is disclosed hereafter.

Bridge 208 is contiguous with support 210. Medially disposed aboutneedle 140 and distally connected to support 210 is shaft 212. Tube hub214, connected to shaft 212 provides a valve leaflet containment basket226 wherein a one-way valve leaflet may be placed and trapped by a tubemounted on hub 214. Basket 226 is better seen in FIG. 10. Basket 226comprises a slot formed by a distal facing side 228 and a proximalfacing side 230, the two sides being connected by a bottom plate 232 andtwo side members 234 and 236.

Side 228 is a smooth planar face comprising a nonprotruding blunt end238 of needle 140. Also seen in FIG. 10 is a valve leaflet disk 240.Disk 240 is made of compliant synthetic resinous material which, underpressure, deforms to seal end 238 of needle 140 against regurgitant flowwhen pressure downstream from needle 140 is greater than upstreampressure. This seal is very important to contain blood within needle 140upon retraction of needle 140. To assure a low resistance to flow fromneedle 140, disk 240 comprises a plurality of raised feet which spacethe distal side of valve disk 240 away from side 230. That spacing andvarious cuts, designated 242, 244, 246 and 248 in distal end 250 of aftpart 194 provide a low resistance pathway for effluent flow from apatient.

Care should be taken that the diameter, designated by A arrows, of disk240 is less than the sum of distances indicated by arrows B and C, butgreater than B plus the diameter of needle end 238 to assure thatregurgitant flow is always stopped, but disk 240 is not inadvertentlyheld in an open condition by a tube stretched over hub 214.

Another embodiment of a one-way valve is seen in FIG. 10A. If hub 214 ismade of sufficiently resilient and compliant material, a leaflet valvemay be integrally molded on the distal end of the hub. In the embodimentof FIG. 10A, a thin planar wafer 252 is integrally connected to a hub214' (which is otherwise similar to hub 214) by a living hinge tocurtail proximal flow through needle 140 at end 238 while beingpermissive to distal effluent flow.

In the embodiment seen in FIG. 6, retractive force is provided by astretched tube. For this purpose, tube 180 is cut to a predeterminedlength allowing for displacement about a proximal and a distal hub andfor a length of the tube which stretches when device 10 is cocked asneedle 140 is pulled outward for use. Tube 180 comprises a proximal end254 and a distal end 256. Tube 180 may be made from any elastic materialwhich is effectively inert to blood and which can provide a return forceof at least four pounds when stretched. It is preferred that the tube becapable of being stretched at least a length of four times its restinglength. However, the currently preferred material is latex. Note that aneedle of one inch in length should require a tube not greater in lengththan about one-half inch.

Barrel section 20 comprises a plurality of internally disposed parts,generally designated 258. Parts 258 comprise an elongated stabilizingkey 260, a distal tube hub 262, an assembly plate 264, an rear deliveryneedle 266 and a needle cover 268.

Stabilizing key 260 is an elongated rod which stretches from assemblyplate 264 to beyond stop 202 when device 10 is assembled and tube 180 isrelaxed. Hub 262 is formed about needle 266 to provide a piercing entryto a low pressure collection tube (not shown) such as a Vacutainer®. Asis standard practice in apparatus which is used to provide entry to lowpressure collection tubes, a pierceable needle cover 268 is provided todeter leakage as collection tubes are replaced.

FIGS. 6, 11, 12, 13 and 14 demonstrate simplicity of assembly of device10. FIG. 6 is representative of parts in a preassembled configuration.Step one in assembly comprises insertion of valve disk 170 into valvecontainment basket 226 as seen in FIG. 11. Note that step one is notrequired when a valve leaflet such as a valve formed by wafer 252 is anintegral part of tube hub 214'.

Attachment of tube 180 to hub 214 (or hub 214' in the case of theembodiment seen in FIG. 10A) is seen in FIG. 12. To assure that tube 180is securely affixed to hub 214 (or 214') it is recommended that anadhesive be applied to a proximal portion of hub 214 (or 214')immediately before tube 180 attachment. A suitable adhesive materialshould be used and care should be taken to assure that no inappropriateblood reactive material is allowed to contact areas where blood mayflow. One adhesive which has provided satisfactory adhesion in models ofthe invention which have been reduced to practice is Duro Super Glue,manufactured and distributed by Loctite Corporation, Cleveland, Ohio44128, commonly known as Super Glue, although other adhesive materialsknown in the art may also be used within the scope of the invention.

Completion of a fluid flow path from needle 140 is seen in FIG. 13. Tube180 is connected on distal end 256 to hub 262. At the same timestabilizing key 260 is engaged in a locking slot 270 (See FIG. 14A)disposed in annular stop 202. Key 260 is formed to slide laterally intoand out of slot 270 and fit snugly therein when tube 180 is relaxed(i.e. during assembly). In this manner, no undue torque or rotationalstress is placed upon frangible bridge 208 during assembly. To provide apathway for key 260 past support 210, a material relieving flat 272 isformed along the plane of travel of key 260 in support 210.

As a next step needle containment section 30 is disposed about theassembled parts. Needle cover 120 comprises a female connecting segment274 which is complementary to the male connector provided by hub 216.Cover 120 is preferably affixed by rotating section 30 relative to hub216 although press-on connections which can withstand pull forcesexerted by an elongating tube or spring or the like may also be used.

As needle cover 120 is connected to hub 216, tube 80 of section 30engages assembly plate 264. Tube 80 is securely affixed to assemblyplate 264 by adhesive or ultrasonic welding processes which are wellknown in the art of plastics assembly. In this manner, a hermetic sealis provided to protect needle 140. As such, sections 20 and 30, incombination provide a housing for needle 140 which may be used withoutadditional packaging for transport.

Attention is now drawn to front face plate 100 of section 30. Face plate100 comprises a proximal surface 276 and a distal surface 278. Disposedin surface 278 is an annular groove 280. Groove 280 completely encirclesthe area where cover 120 integrally connects to plate 100 and a ring hub282 which is integral with the proximal end of cover 120. Hub 282 alsointegrally connects ring 110 to section 130. Groove 280 is of sufficientdepth in plate 100 to permit facile frangible separation by a positivetug, twist or pull on ring 110 while retaining sufficient material toprovide a hermetically sealed container and a sturdy and safe transportcontainer. Products having such seals are available in commerce.

Frangibly separating ring 110 and cover 120 from section 30, as seen inFIG. 2, causes tube 180 to be stretched between separating hubs 214 and262 as is best seen in FIG. 15. Note that needle hub part 160 and, inparticular, locking slot 270 is pulled away from key 260 by the sameaction. For this reason, it is advisable to make groove 280 and cover120 somewhat asymmetric to minimize rotation during tube extension. Oneof the material attributes which permits tube 180 to be used to storeenergy to retract needle 140 and to act as a pathway for fluidcommunication between needle 140 and needle 266 is that the internallumen of a tube remains patent when stretched. The diameter of the lumenis reduced but not closed as the tube elongates.

When ring 110 and cover 120 are separated from section 30 by frangingplate 100 at groove 280, an annular hole 284 is created in plate 100. Asseen in FIG. 14, when needle/hub part 160 is pulled proximally, cover120 and then yoke 130 are pulled through hole 284. The slanting annularsurface 218 of yoke 130, as best seen in FIGS. 7-9, comprises a proximaldiameter which is smaller than the diameter of hole 284 and a distaldiameter which is larger than hole 284. However, the distal diameter issuch that yoke 130 passes through hole 284 due to the "give" of materialfrom which section 30 is made. Groove 200 has a width which permitsplate 100 to be engaged therein when yoke 130 is pulled through hole284. The proximal face of stop 202 has a diameter which is greater thanhole 284 causing part 160 to be firmly affixed to plate 100 when yoke130 passes through hole 284 as seen in FIG. 14.

Once the procedure involving needle 140 is completed, and preferablywhile needle 140 is yet disposed in a patient's blood vessel, needle 140is automatically retracted. The retraction process involves (1)hingeably relocating protective flap 90 (as seen in FIG. 4) and (2)applying pressure upon part 206 through area 148 of tube 80 to frangiblyseparate fore part 190 from aft part 192 by breaking bridge 208 ofneedle/hub part 160.

Flap 90 is commonly released from attachment to tube 80 at groove 146 byinserting a thumb or finger under a portion of flap 90 and lifting.Bridge 208 is broken by applying pressure, preferably between a thumband forefinger, in the direction of arrows 284 and 286. Franging forces(i.e. shear forces) are thus applied through area 148 to part 206 and aninferior portion of tube 80 to support 210. Note that substantially allother forces applied to bridge 208 are those of tension caused bylongitudinal stretching of tube 180. For this reason, bridge 208comprises a geometric shape which is conducive to breaking when imposedupon by shear forces, but capable of withstanding large amounts oftension.

One of the major reasons that substantially all of the forces placedupon bridge 208 during extending a retractive mechanism is a closetolerance held between needle 140 and fore part 190. As mentionedherebefore, part 190 is made to be free of needle 140 such that it canslide thereon. To maintain the tight tolerance and to provide aninexpensive method for manufacture of part 160, needle/hub part 160 ispreferably molded as a unit about needle 140. Part 160 is preferablyinjection molded.

To permit fore part 190 to be molded about needle 140, yet remainslidably free, a thin coat of mold release is applied about needle 140prior to molding. By applying a coat 288 of mold release in an areawhere fore part 190 is molded, fore part 190 remains only slidablyattached to needle 140. Of course, at the distal end 290 of needle, aftpart 194 is firmly and securely affixed by the molding process causingneedle 140 to be retracted when tube 140, attached to aft part 194, ispermitted to contract. Note that, when needle 140 is retracted throughyoke 130 and hub 132, the only access into tube 80 is through hole 150which has substantially the same diameter as needle 140. Of course, onceneedle 140 is retracted, it is irretrievably held inside tube 80 by arelaxed tube 180.

Except for needle 140, which is made of medical grade steel, needle/hubpart 160 is made from a moldable material having sufficient tensilestrength to withstand pull pressures of device 10 yet be facilelyseparated at bridge 208. As such, part 160 is preferably made ofsynthetic resinous material, such as polyurethane, polypropylene orpolyethylene. For an experimental device, the synthetic resinousmaterial used was polyurethane sold as Quik Cast distributed by TAPPlastics, Dublin, Calif. 94568, however many currently commerciallyavailable materials may be used within the scope of the invention.

Barrel section 20 is likewise preferably made from synthetic resinousmaterial. Barrel section is also preferably molded about rear deliveryneedle 266. The same material which is used in currently commerciallyavailable barrels used with vacuum based blood drawing tubes (e.g.Vacutainer® tubes) may be used. Needle cover 268 may be the same asVacutainer® barrel needle covers now in use.

Needle containment section 30 is preferably made by a single moldedprocess. Mold material should be selected such that it providessufficient material strength to engage and hold the hub 132 connectionthrough the pull process, sufficiently flexible when made as a thinmembrane to permit distortion sufficient to break bridge 208, andfrangibility for facile opening as at groove 280. The material ispreferably a synthetic resinous material and may be polyethylene,although other materials meeting flexibility, medical compatibility andstrength requirements may be used.

Reference is now made to FIGS. 16-20 which relate to another embodimentof the invention. This embodiment is similar to the embodiment seen inFIGS. 6-14 in general form and function, but does not depend upon afrangible part to release and retract the needle. As seen in FIG. 16, aneedle/hub assembly 300 comprises two parts, designated fore part 302and aft-part 304, which are formed about a needle 140. Parts 302 and 304may be molded about needle 140 simultaneously. Part 302 is preferablymolded about a segment of needle 140 to which a mold release has beenapplied, as earlier described. (See FIG. 5.)

Fore part 302 comprises a central body 306 and a pair of outwardlyextending wings or arms, individually designated 308 and 310. Each arm308 and 310 is connected to central body 306 by a biased hinge 312 and314, respectively. The biasing of hinges 312 and 314 is preferablyformed as a part of the molding process. Such hinges are well known inthe art; as an example note hinges on telephone connectors. Each arm308,310 is biased to extend outwardly from central body 306 apredetermined distance. Disposed at the outer end 318,320 of each arm308,310, respectively, is an inwardly projecting latching extremity322,324.

Central body 306 comprises a cover connecting hub 132' which is similarin form and function to hub 132. A portion 316 is disposed distal to hub132' where hinges 312 and 314 are attached.

Aft part 304 comprises a central body part 326, a pair of outwardlyextending and biased wings or arms 328 and 330 and a tube hub 332. Wing330 comprises an inwardly projecting strut 334 which ends at a clampingface 336. In opposing fashion, wing 328 comprises an inwardly projectingjaw 338. Function and use of the various parts of fore part 302 and aftpart 304 are disclosed in detail hereafter.

As mentioned earlier, fore part 302 is preferably molded about needle140, but not attached thereto, except by the natural engagement providedby materially surrounding the circumference of a portion of the needle.This permits fore part 302 to be rotated 90° and moved into linkableproximity with aft part 304 as seen in FIG. 17.

Parts content in this second embodiment of blood withdrawal device 10 isbest seen in FIG. 21. This second embodiment comprises a barrel section20', tube 180, needle hub assembly 300 and needle containment section30.

Barrel section 20' is substantially the same as barrel section 20 exceptfor the substitution of a guide-catch cylinder 340 integrally andmedially disposed on a fore portion of barrel section 20' rather thanstabilizing key similarly disposed upon barrel section 20.

Guide-catch cylinder 340 is best seen in FIG. 20. As seen therein,barrel 20' comprises barrel 70, a substantially closed fore face 342 ofbarrel 70, distal needle hub 262, providing access to needle 266, andguide-catch cylinder 340. Guide-catch cylinder 340 is medially disposedupon face 342 and extends in elongated fashion in line with of needle140 (not seen in FIG. 20). Hub 262 is medially disposed inside cylinder340 along the same line.

Cylinder 340 comprises a plurality of slots which provide relief foroutwardly biased members of parts 302 and 304, travel guide for assembly300 and catch stops which selectively maintain parts of assembly 300 ina proximal position while needle 140 is in use. A first slot 346,disposed to act as a guide, extends the length of cylinder 340. In thisembodiment device 10 is assembled to dispose a portion of wing 330 inslot 346.

Disposed at its distal end, cylinder 340 comprises a second slot 348offset at 90° from slot 346 and having a length which is adequate forrelief from compression of wing 308 when assembly 300 is distallydisposed before use. Likewise, cylinder 340 comprises a third slot 350similar to slot 348 and juxtaposed 180°, therefrom, to provide relieffrom compression of wing 310. A fourth slot 352 of cylinder 340 isdistally disposed 180° from slot 346 and provides before-use relief fromcompression for wing 328. Should an outwardly biasing material be usedin manufacturing assembly 300 which does not take a set after timebetween assembly and use, it is not necessary to provide slots 348, 350and 352.

Cylinder 340 provides openings for four slots at its proximal end 353,i.e. slots 346, 354, 356 and 358. As mentioned earlier slot 346 providesa guide for assembly 300 by containment of wing 330. Longitudinallyslots 354 and 356 are respectively aligned with slots 348 and 350. Slot354 comprises a catching edge 360 for end 318 of wing 308 while slot 356comprises a catching edge 362 for end 320 of wing 310. Slot 358 isaligned with slot 352 and provides a catching edge 364 for wing 328 asis described in detail hereafter. Each slot has a depth such that incombination latch portions of wings 308, 310 and 328 occur substantiallysimultaneously.

Latching operation of elements of assembly 300 is best seen in FIGS. 18and 19. Each of FIGS. 18 and 19 are divided by dashed lines into threesections (A, B and C) to demonstrate operation of fore part 302 and aftpart 304 of assembly 300 at different positions along the length ofcylinder 340. Note that wings 328 and 330 are vertically disposed inFIG. 18. Wings 308 and 310 are vertically oriented in FIG. 19 as partsof assembly 300 in FIG. 19 are rotated by 90° relative to parts in FIG.18.

It is particularly important to note that wing 328, as seen in FIG. 18Aand 18C, extends superiorly from central body part 326 along a line 366to pivot arcuately upward at arc 368 to join a superior line 370.Further, line 370 ends at a latch point 372. From latch point 372, theshape of wing 328 is further defined by an inwardly progressing line 374and an acutely connected line 376 which, in combination, demarcate jaw338.

As seen in FIG. 18A, wherein assembly 300 is residing distally withincylinder 340 and tube 80, wing 330 is free to move in the longitudinaldirection of needle 140 guided by slot 346. In the same assembly 300position, wing 328 is disposed in an uncompressed or relaxed statewithin slot 352. When assembly 300 is pulled proximally to a cocked anduseful state as seen in FIG. 18C, assembly 300 passes through anintermediate state seen in FIG. 18B. As assembly 300 is moved proximallyfrom the state seen in FIG. 18A, the form of wing 328 formed alongarcuate line 368 permits wing 328 to be collapsed such that line 370 ofwing 328 coincides with the cylindrical inner surface of cylinder 340.In this manner, the aft part 304 of assembly 300 is facilely allowed tomove through cylinder 340.

Note that compression of wing 328 as seen in FIG. 18B causes jaw 338 tocompressively pinch tube 140 stopping any flow of liquid therethroughwhile wing 328 is between slots 352 and 358. Moving assembly 300proximally to the position seen in FIG. 18C permits wing 328 to be oncemore relieved as it is biased to enter slot 358. Once there, a latchformed at latch point 372 and along line 374 is caught by edge 364,firmly retaining assembly 300 with tube 140 in a stretched condition.

Referring now to FIG. 19, device 10 has been rotated 90° clockwiserelative to a view of the needle 140 end of the device. In FIG. 19 wings308 and 310 are vertically oriented. Each arm 308,310 resides in anon-compressed state in slots 348 and 350, respectively. Arm 308comprises an arcuate surface 378, similar to the wing 328 arcuatesurface along line 368, which provides a facile release from slot 348.Arm 310 comprises a similar surface 380 for facile release from slot350.

As assembly 300 is pulled proximally from the state seen in FIG. 19A tothe state seen in FIG. 19B, arms 308 and 310 are compressed inwardly.Each arm 308 and 310 comprises a latching foot, respectively designated382 and 384, which engages and grips a distal annular surface 386 ofcentral body 326. In this manner, fore part 302 is releasibly adjoinedto aft part 304 while assembly 300 is pulled forward to a cockedposition. In its most proximal position, arms 308 and 310 are outwardlybiased into slots 354 and 356, respectively. In this position, feet 382and 384 catch against edges 360 and 362 to form a permanent latchthereby. Note that outward biasing of arms 308 and 310 release the graspof feet 382 and 384 against surface 386, thereby releasing the grip ofaft part 304 by fore part 302.

When the grip of aft part 304 is so released, needle 140 is relieved ofproximal containment in tube 80 when aft part 304 is triggered to areleased state to be distally displaced by contraction of tube 180.Referring once more to FIG. 18C, aft part is released from a cockedstate by depressing area 148 in the direction of arrow 388. Suchdepression forces wing 328 inward until the part of wing 328 along line374 and latch point 372 clears edge 364. Contraction of elastic tube 180retracts aft part 304 and needle 140, to which the aft part is securelyaffixed, into the distal section of tube 80 seen in FIG. 18A. Fore part302 remains proximal in tube 80 to effectively plug the hole formed byremoval of hub 282 and collar 114. Note that fore part 302 comprises athreaded hub 132', similar to hub 132.

Reference is now made to FIG. 21 where an exploded view of parts whichare comprised in the alternate embodiment seen in FIGS. 16-20 is seen.The alternate embodiment parts comprise barrel section 20', tube 180,needle hub assembly 300 and needle containment section 30.

Assembly of the parts seen in FIG. 21 into a complete needle retractingdevice 10', which is functionally equivalent to device 10, involves thefollowing steps:

1. Affixing tube 180 to hub 332;

2. Biasing wings 308, 310 and 328 inwardly and sliding assembly intocylinder 340 for engagement with slots 348, 350 and 352, respectively;

3. Affixing tube 180 to hub 262. Note that access to hub 262 is providedthrough slot 346;

4. Laterally displacing section 30 such that the threaded connectingsegment 274 of needle cover 120 engages hub 132';

5. Rotating section 30 to affix hub 132' to needle cover 120 (assembly300 is restrained from rotating because wing 330 is disposed in slot 346both during assembly and cocking procedures);

6. Affixing section 30 to section 20', preferably by application ofadhesives or by ultrasonic welding to form a hermetically sealed packageabout needle 140.

Reference is now made to FIGS. 22 and 23 where a catheter insertionapparatus 400, another embodiment of the invention, is seen. A closed,transport compatible package of apparatus 400 is seen in FIG. 22.Exteriorly, apparatus 400 is seen to comprise a pull ring 110' affixedto and integral with a front face plate 100', which is similar to faceplate 100. Face plate 100' is integral with a tube 80' which is alsosimilar in form and function to tube 80. Face plate 100' also comprisesan annular frangible segment 112' which permits ring 110' and a collarportion 114' of plate 100' to be frangibly separated from plate 100'when pulling a needle assembly proximally from tube 80' for use.

Tube 80' comprises a flap 90' which, similar in form and function toflap 90, is releasibly affixed to a groove 146' and on an opposite endattached by a living hinge 142' to tube 80'. Tube 80' is elongated tofully contain a needle 140' used in catheter insertion and a needlewithdrawal mechanism 402, as seen in FIG. 23.

At its distal end, tube 80' comprises an annular raised section 404which acts as a handle during the needle pulling procedure. Furtherapparatus 400 comprises a distal plate 406 which is securely affixed atthe distal end 408 of tube 80' to enclose and hermetically seal needle140' and withdrawal mechanism 402 inside tube 80'.

Withdrawal mechanism 402 comprises a needle/hub part 160' which issimilar to part 160 in form and function. Basic ways in which part 160'departs from the form of part 160 is found at the proximal and distalsegments of part 160'. Proximally, part 160' comprises a secondaryconnection 412 for a transcutaneous catheter 410.

Such catheters and catheter connections are well known in thetranscutaneous catheter art. Also, needles used with transcutaneouscatheters are readily available. A common source is Becton DickensonCorporation of Franklin Lakes, N.J. 07417-1883. A current source forsuch catheters is Abbot Hospitals, Inc., North Chicago, Ill. 60064. Thematerial from which tube 80' and plate 406 is made is similar tomaterials prescribed for tube 80.

Distally part 160' comprises a connection 414 whereby a return energystoring component 416 is affixed to a hub 418 portion of part 160'. Asseen in FIG. 23, part 160' comprises catheter needle 140', a fore part190' proximal to the sharp end of needle 140', a central part 192', andan aft part 194'. With the exceptions of proximal and distal connectionsof mechanism 402, parts 190', 192' and 194' are substantially the samein form and function to parts 190, 192 and 194. A bridge part 208' andupwardly extending part 206', each being respectively similar in formand function to bridge 208 and part 206, are similarly inwardly disposedfor compressible access via a depressible area 148' of tube 80'.

Markedly different, although within the scope of the invention is returnenergy storing component 416. Component 416 comprises a plurality ofpiston head parts 420, 422 and 424 which communicate with an inner wall426 of tube 80' to effectively pull and retain a vacuum as the mechanismis moved proximally. The vacuum contained in tube 80' provides the forcewhich retracts needle 140' when bridge 208' is frangibly broken. Toprovide an adequate retraction force, parts 420, 422 and 424 must createa differential force of at least four pounds to overcome forces ofstiction in both the needle and other retracting mechanisms. Forapparatus 400 to have substantially universal use, a minimum atmosphericpressure of ten pounds per square inch is assumed. For a minimumpressure of four pounds realized from an atmospheric pressure of tenpounds per square inch, each part 420, 422 and 424 must have a minimumarea of four tenths of a square inch. As parts 420, 422 and 424 areessentially circular planes, their diameter must be a minimum of 0.36inches (0.9 centimeters).

Parts 420, 422 and 424 are securely affixed to a medially disposedpiston hub 428 which is in turn likewise affixed to mechanism 416 viaaft part 194'. As indicated by dashed lines 430, needle 140'communicates with hub 428 via part 194. Hub 428 is a hollow vessel whichis completely sealed, except for a gas communicating plug 432 disposedproximal from part 424.

Plug 432 is made from a hydrophobic material which is permissive topassage of gas (air), but retards flow of water based liquids (such asblood). The preferred material is Goretex, a material available from W.L. Gore Company, Arizona, USA. Plug 432 is securely affixed to hub 428to provide a pathway for gas to relieve pressure as blood iscommunicated into hub 428 through needle 140'.

Hub 428 is made from either translucent or transparent materials throughwhich blood may be seen. Thus, by providing the pathway from needle 140'into hub 428 and permitting air to escape from hub 428 as influent bloodarrives, hub 428 provides a visually determinable blood "flash" which iscommonly used to ascertain entry of needle 140' into a blood vessel.

To use apparatus 400, ring 110' and collar 114' are frangibly separatedfrom plate 100'. Needle cover 120', needle 140' and catheter 410 arepulled from tube 80' until mechanism 402 is firmly attached to plate100'. By this action a vacuum is created in the portion of tube 80'which is distal to part 420. Cover 120' is removed and needle 140' andcatheter 410 are transcutaneously inserted into a patient following goodmedical practices. When needle 140' enters a blood vessel, blood iscommunicated to hub 428 through which a blood "flash" communicates tothe attending technician that the vessel has been entered. At thispoint, flap 90' is lifted to provide access to area 148'. A portion ofarea 148' is depressed to frangibly break bridge 208' which releases theaft portion 194' of mechanism 402 to be retracted by force stored viaparts 420, 422 and 424 in cooperation with tube 80'. Needle 140' isthereby withdrawn. Note that the only pathway through which blood may becommunicated upon withdrawal of needle 140' is into tube 80'. Thislimitation upon needle withdrawal is a definite advantage overnon-selfretracting needle systems currently in use. Under appropriatelycontrolled conditions, catheter 410 is removed for attachment to othermedical devices.

Another catheter embodiment is seen in FIG. 24 wherein a catheter 410'has a connecting end 500 which comprises a fore section 502, a medialsection 504 and an aft section 506. Aft section 506 comprises connectingparts which are separable as earlier described secondary connection 412is separable. Fore section 502 securely affixes catheter 410' to therest of connecting end 500. Section 504 is medially interposed betweensections 502 and 506 and is normally adhesively affixed thereto. Suchadhesives are well known in the art.

As seen in FIG. 25, section 504 comprises a tubular member 508 which hasa central orifice 510 provided as a fluid pathway. An outside ringsection 512 partially encircles member 508. Disposed within section 512are a pair of rigid supports 514 and 516. Each support 514 and 516comprises a radially extending inward bend 518 and 520, respectively.Supports 514 and 516 with bends 518 and 520 are disposed to constrictorifice 510 when squeeze pressure is applied in the direction of arrows522 and 524, seen in FIG. 26. In this manner orifice 510 may be closedto prevent escape of blood through catheter 410' when changingconnections to the catheter after it has been inserted into a vessel ofa patient.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by Letters Patent is:
 1. Adisposable, single-use, self-retracting catheter insertion needleassembly and housing in which the needle assembly is stored andtransported, said needle assembly comprising:the housing having amanually distortable section, providing a medically safe transportpackage for the needle assembly, and having an exit and reentry end fora portion of the needle assembly; a needle cover disposed for transportwithin the housing and being a part of the portion; an elongated medicalneedle disposed within the housing and further within the needle coverand having a sharpened end disposed toward the exit and reentry end ofthe housing; a catheter disposed about the elongated needle; a needlecover attachment hub disposed about said medical needle and separablyattachable to and detachable from the needle cover, said coverattachment hub being disposed about said needle during transport andbefore and during blood withdrawal but separable therefrom; said coverattachment hub further comprising a latch which, for needle insertion,is positioned to lock said needle assembly at a predetermined positionrelative to said exit and reentry end whereat the needle extends outwardfrom said housing and is thereby positioned for use; a distal part ofthe assembly firmly affixed to said medical needle at at least an end ofthe assembly distal from the sharpened end, said distal partcomprising:a separable attachment between the distal part and said coverattachment hub; an attachment release apparatus integrally associatedwith said separable attachment and disposed in close communication withan internal surface in close communication with the distortable sectionof said housing such that the release apparatus is actuated by manualdistortion of that section of said housing; means for affixing saidneedle assembly to a linear motion force storage apparatus which derivesreturn energy for needle retraction from needle extension through theneedle exit and reentry end.
 2. A disposable, single-use,self-retracting catheter insertion needle assembly according to claim 1wherein the catheter has a connecting end which comprises a section, aportion of which is a tube made of deformable material comprising afluid flow pathway and another portion of which is a collar about thetube which may be squeezed to occlude the pathway.
 3. A disposable,single-use, self-retracting catheter insertion needle assembly accordingto claim 1 wherein the separable attachment includes a frangible part.4. A disposable, single-use, self-retracting catheter insertion needleassembly according to claim 1 wherein the linear motion force storageapparatus comprises an elastic tube.
 5. A disposable, single-use,self-retracting catheter insertion needle assembly according to claim 1wherein the linear motion force storage apparatus comprises a means forstoring energy by drawing a vacuum.
 6. A method for percutaneouslyinserting a catheter into a patient using a self-retracting medicalneedle and associated apparatus comprising the steps of:providing theneedle, sheathed by the catheter, and associated apparatus comprising ahousing which contains the sheathed medical needle, a cover for thesheathed medical needle and a cocking and releasing mechanism; frangiblyseparating the cover from the housing; pulling the cover outward fromthe housing to extend needle and catheter sheath from the housing and tocock the cocking and release mechanism; removing the cover to bare theneedle preparatory to a transdermal needle and catheter insertionprocedure; emplacing fore-portions of the needle and the catheter withina blood vessel; distorting the housing to disengage a needle affixedportion of the cocking and release mechanism thereby returning theneedle to the safe containment within the housing while the catheter isretained within the blood vessel; detaching the catheter from theapparatus.
 7. A transcutaneous, self-retracting needle, catheterinsertion apparatus comprising:an elongated housing comprising aflexible compressible section; a transcutaneous catheter disposed withinsaid housing; an insertion needle sheathed by said catheter; an energystoring memory element which stores energy as the needle is pulledoutward from said housing at a needle exit and reentry end of thehousing; an intermediate latch and release mechanism integrally disposedbetween said memory element and insertion needle, said mechanismcomprising:a latch portion, disposed proximal to the exit and reentryend, for latching the needle and catheter in a proximal position forinsertion of said needle and catheter into a blood vessel, theproximally disposed latch portion being free to slide upon said needle;a portion, disposed distal to the exit and reentry end relative to theproximally disposed latch portion, securely attached to said needle; amedial portion disposed between the proximal portion and distal portion,the medial portion comprising a means for separating the distal portionfrom the proximal portion by depressing the housing segment.
 8. Anapparatus according to claim 7 wherein the housing comprises aprotective sterile barrier for protecting the needle and catheter priorto extention from the housing.
 9. An apparatus according to claim 7wherein the energy storing element comprises an elastic tube.
 10. Anapparatus according to claim 7 wherein the latch and release mechanismcomprises a frangible part.
 11. An apparatus according to claim 7wherein the housing comprises a safe and medically efficient catheterand needle transport container prior to pulling the needle proximally.